The Spaceflight Meteorology Group
Interpreting SMG's Shuttle Landing Site Forecasts
Cloud heights are reported in hundreds of feet. To de-code
the cloud height, add two zeros to the right side of the
(5 = 500 feet while 150 = 15,000 feet)
CLR --- Clear --- No Cloud Coverage
FEW --- Few --- Greater than 0/8 and less than 3/8 Cloud Coverage
SCT --- Scattered --- 3/8 or 4/8 Cloud Coverage
BKN --- Broken --- 5/8 through 7/8 Cloud Coverage
OVC --- Overcast --- Total Cloud Coverage
A cloud "ceiling" is the lowest BKN or OVC layer.
Following the cloud section, visibility is reported in statute
Follwing visibility, wind direction and speed are reported.
The first three digits are the wind direction, (the direction
the wind is coming FROM), reported to the nearest ten degrees
on a magnetic compass. (050 = 50 degrees while 360 = 360 degrees)
Wind speed and peak winds are reported in knots. Peak winds
refer to the highest wind speed expected to occur during the
The final optional group contains any remarks that the
forecaster feels to be important.
(SHRA WI 30NM = rain showers within 30 nautical miles)
A sample forecast might read:
KSC FEW020 SCT080 OVC100 7+ 15007P13
SHRA WI 30NM
This would be decoded: Landing site - KSC
Sky Conditions: 2,000 feet FEW (0/8 through 2/8 Cloud Coverage)
8,000 feet SCT (3/8 or 4/8 Cloud Coverage)
10,000 feet OVC (Total Cloud Coverage)
(The "ceiling" would be at 10,000 feet
because that is the first layer of >=
5/8 cloud coverage.)
Visibility: Greater than 7 Statute Miles
Wind: From 150 Degrees (SE) at 7 knots, peaking to
Remarks: Rain showers within 30 nautical miles.
Following the forecast section, flight rule violations are
highlighted on a station by station basis.
Violations Include: CIG = Ceiling
SHRA = Rain Showers
TSRA = Thunderstorms
XWIND = Crosswinds